Steam generator



June 24, 1930. l N. FoRSsBLAD 1,766,989

STEAM GENERATOR l Filed uar'ch so. 1927 Patented June 24, 1930 NILSFORSSBLAD, OF VILLA EKBACKA, VASTERS, SWEDEN STEAM GENERATOR.

Application filed March 30, 1927, Serial No. 179,677, and in GneatBritanApril 20, 1,926..A

My invention relates to an improved sectional steam generator',particularly suitable for gaseous, liquid, or pulverized fuel, of thetype wherein the walls of the furnace or s combustion chamber aredirectly formed by the water-cooled metal surfaces or heating surfacesof the generator.

It has already been proposed to form the walls of the combustion chamberof such 1o steam generators of vertical tubes rolled or otherwise fixedat their upper Vand lower ends into horizontal drums. According to mypresent invention, the walls of the combustion chamber are composed of anumber of sections, each consisting of vertical tubes fixed betweensubstantially horizontal headers. The said headers are connected eitherto one or more vertical drums traversing the centre of the combustionchamber,

or to separate upper and lower collecting vessels which are directlyconnected together by downcomer-s separate from the yvertical steamgenerating tubes.

In comparison with prior construction,

steam generators built according to my invention are simple and lessexpensive as the number of drums is less. The difference is notableespecially at high steam pressure. Further the vertical tubes can bemade straight which is not always the case where they are connected todrums. Bya central disposition of the collecting vessel, it is possibleto construct a generator of very large size, the maximum diameter beingpractically equal to twice the maximum tube length available forproviding the communication between said central vessel and theVheaders.

An important advantage of my invention 0 is the facility ofstandardizing the construction attained hereby, the building of steamgenerators yof dierent sizes from different numbers of equal sectionsbeing made possible.

The accompanying drawings illustrate two arrangements of steamgenerators according to this invention but the invention is not limitedthereto. Figure l is a vertical section and Figure 2 a horizontalsection of 59 one arrangement while Figure 3 is a vertical section,Figure 4; a vertical section at right angles toFigure'S, and Figure 5 ahorizontal section of another arrangement according to this invention.

Referring to Figure 1, the walls of the combustion chamber are formed bytubes l fixed at their ends in headers 2. These heador to superheaters,economizers, air preheaters or other accessories, or directly to thechimney. Burners 8 are shown in the lower part of the combustion chamberor furnace, tangentially arranged. They may also be arranged radially.

The drum 4 may be arranged in any suitable manner for collecting thesteam, for instance, it may have a hemispherical top portion, or it maybe combined with a separate steam collector, if necessary. For highpressures, the drum 4 may be replaced by a number of parallel drums ofsmaller diameter. The vertical tubes 1 may be of the usual form orprovided with longitudinal fins or plates lling the space between them.In the arrangement shewn in Figures 3 to 5, l are the vertical tubes, 2the headers, 3 the connecting tubes, 6 the outer lining and 7 the flue.Instead of a vertical drum running down through the generator, ahorizontal drum 9 may be employed in this arrangement receiving theinner ends of the upper connecting tubes 3and a corresponding lower drum11 for the lower tubes 3 is connected to the former by the downcomertubes 10. The lower drum is shewn in the shape of a vertical cylinder,or it may be horizontal and parallel to the upper drum 9. The down tubesl0 may be placed outside thecombustion chamber if desired.

I claim as my invention An internally fired radiant heat boilerconsisting, in combination, of an open cornbustion chamber formed of acontinuous water wall made up of independent sections each having anupper and a lower header connected by rows of closely spaced verticaltubes, a central column having a steamand water space therein extendingthe height of the combustion chamber and insulated throughout asubstantial portion of its lower part against the heat of the combustionchamber, and substantially horizontal tubes connecting the said headersof each section to said central column adjacent its top and bottom.

In testimony whereof I have signed name to this specification.

NILS FORSSBLAD.

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